A Comparative Account of External Sculpture of the Eggs of Two Tiger-Moths (Erebidae: Arctiinae: Lepidoptera) from India

Abstract

This study aimed to update the taxonomic data of two tiger moths which were earlier based upon the taxonomic characteristics of adult specimens only like male and female genitalic features. This study is an attempt to prove that the ultrastructural characteristics of the egg chorion of these tiger moth species are also important and they can be used in early taxonomic identifications of these species based on egg characteristics as they are also found to be species-specific. A scanning electron microscope was used to inspect, characterize and depict eggs of two species referable to Spilarctia Butler and Cladarctia Koda of the Erebidae family. The descriptions and comparative morphological analyses of the eggshells of Spilarctia multiguttata (Walker) and Cladarctia quadriramosa (Kollar) were compiled to present the structural complexity of these tiny eggs and depict the distinct patterns of structural features including the central micropylar pit, micropylar rosette, number of micropyles and aeropyles. The SEM analysis revealed their unique architecture which allows for unrestricted exchange of oxygen and carbon dioxide while limiting water loss because of the presence of minute air pores all over the chorion. From the results, it is evident that the ultrastructural egg chorion characters are of great taxonomic value at specific as well as generic levels and these types of investigations must be amplified to improve and escalate the morphological personation of tiger moths.